(The Root) — I'm getting close to that point in my life where I recognize that a lot of the music I hear on the radio originated somewhere else and feel the need to school anyone under the age of 18 about it. Whether you're a music aficionado who loves to study the history of a song or you just want to show your little cousin why "Otis" is so hot, WhoSampled is a must-have.

The app for the iPhone scans your personal music library and shows you all the samples, covers and remixes of each track on your playlists. With a database of more than 150,000 songs by more than 54,000 artists, you can find out the background of practically any song that was sampled from another source. Get extensive and detailed information about the sample, including what part of the song it was taken from.

You can also do a side-by-side comparison of the two songs and listen to the originals on YouTube, SoundCloud or DailyMotion. If you don't find your song in the exhaustive WhoSampled library, you can create an account on WhoSampled.com and add it yourself.

This app is cool for a couple of reasons. Not only am I able to stay on top of my music history, but I also gained a better appreciation for current popular music. Using the app, I found out that "Mercy" by Kanye West, No. 1 on Billboard's R&B/Hip-Hop chart this week, was sampled from "Super Beagle" by the group Dust a Sound Boy. But in listening to them side by side, I could hardly pick out the similarities. To me, this was a testament to the creativity required by any artists to create a new sound, whether or not they play all their own instruments.

The WhoSampled app costs $2.99 and is available for iPhone or iPad, with an Android version coming soon.